This section is from the book "The Hygienic System: Fasting And Sun Bathing", by Herbert M. Shelton. Also available from Amazon: The Hygienic System Vol III Fasting and Sun Bathing.
Metabolism is lowered from one-fourth to two-fifths during the fast. This falls quite rapidly during the first part of the fast until the true physiological minimum for metabolism is reached. From this point on, until the return of hunger, metabolism is maintained at a fairly uniform level. If food is not consumed when hunger returns there follows, soon, a rapid dropping of metabolism to new low, but pathological levels.
During the first fifteen days of Levanzin's fast there was an appreciable decrease in oxygen consumption and in carbon-dioxide production. During the first seven days of the fast he consumed 352.6 liters of oxygen and produced 260.4 liters of carbon-dioxide. During the second half of the first fifteen day period he consumed 303.2 liters of oxygen and produced 219.5 liters of carbon-dioxide. During the first half of the second fifteen day period he consumed 272.3 liters of oxygen and produced 193.7 liters of carbon-dioxide. During the last half of the second period he consumed 270.3 liters of oxygen and produced 192.9 liters of carbon-dioxide.
In a general way the changes in the metabolism of proteins, fats, etc., run fairly parallel with carbohydrate metabolism. Nitrogen metabolism in the fasting baby supplies a remarkable apparent exception to this. Nitrogen excretion tends to increase from day to day, rather than decrease. The small supply of glycogen possessed by the baby is rapidly oxidized and it is compelled to draw upon its proteins for maintenance. It will be recalled that the growing infant utilizes its proteins primarily for the building up of tissue and that it, normally, excretes less nitrogen than is consumed.
Dr. Kunde quotes Dr. Carlson who suggests that "the higher metabolism after prolonged fasts may be due to temporary excess activity of such glands as the thyroid and the gonads that seem to have direct effects on the metabolic rate.
"It is well established that fasting induces a marked atrophy of these glands. The recuperation of these glands on the resumption of eating may carry them for a while beyond the level of activity normal for the age of the subject. This would in all probability lead to a higher metabolism."
That this explanation is incorrect is evident from the following considerations:
(1) Fasting does not cause atrophy of the glands. Atrophy takes place in starvation.
(2) There is no reason to believe that atrophied glands will function excessively. They would be more likely to function deficiently.
(3) The increased metabolic rate begins immediately upon the resumption of eating, before the "atrophied" glands have had time to recuperate.
John Arthur Glaze records in the American Journal of Psychology that one result of a two weeks' fast which he observed was a marked intensification of the sexual impulse after the fast was over, though it was largely inhibited during the fast. This certainly cannot be due to atrophy of the gonads. It indicates increased gonadal efficiency corresponding to the increased acuteness of the senses of sight, taste, smell, hearing and feeling. We would not attribute better eyesight following a fast to optic atrophy, or better hearing to auditory atrophy.
One is constrained to ask, what is the "level of (glandular) activity normal for the age of the subject?" The level of activity presented in the old man and woman of today is a pathological level rather than a physiological or biological norm.
Kunde dwells at length on the increased metabolic rate (oxygen consumption) following a fast and suggests that this may be due to the cell membranes becoming more permeable to food than before the fast. The doctor does not seem to understand the significance of toxin elimination by fasting. Lack of understanding of toxemia and its role in reducing physiological processes leads to much misinterpretation of phenomena.
Kunde continues: "But the fact that there is a tendency for the metabolic rate to return to its former level points to internal coordinating processes that are not permanently altered by fasting." But this may point to a speedy reproduction of the pre-fast-ing "physiological" condition by a return to the former mode of living. Living cannot be left out of the formula. What is meant, for example, by a normal diet? New protoplasm built by a "normal" diet may not be of better quality than that lost during the fast.